Open-Mesh offers mesh-network WiFi extension for $49

From Slash Gear -

The Open-Mesh Mini-Router not only extends Wi-Fi coverage but allows you to run a couple of networks concurrently, (e.g. one is open for guests while the other is WPA-secured for personal use). It even can be configured in a variety of bandwidth throttling and firewall options. The Open-Mesh Mini-Router retails for $49. Alternatively, since it’s all based on an open-source project called ROBIN, you can flash a compatible router yourself should you be feeling technical.

Source article here.